Preparation of alumina-platinumhalogen catalyst



Patented Jan. '15, 1952 PREPARATION OF ALUMINA-PLATINUM- HALOGENCATALYST Vladimir Haensel, Hinsdale, m., assignor to Universal OilProducts Company, Chicago, Ill., a corporation of Delaware No Drawing.Application June 17, 1949,

Serial No. 99,869

(Cl. 25H) Claims. 1 This is a continuation-in-part of my copendingapplication Serial No. 788,672, filed November {28, 1947, now patent No.2,479,109, August '16,

This invention relates to the manufacture of ,catalysts and particularlyto the manufacture of platinum-containing catalysts. In anotherembodiment the present invention relates to a novel composition ofmatter comprising these catalysts.

Platinum-containing catalysts and various methods of manufacturing thesame have heretofore been suggested. These catalysts have been limitedcommercial acceptance because of the high cost thereof. The presentinvention is based on the discovery that exceptionally good catalystsmay be prepared by specific methods of preparation to be hereinafterdescribed in detail.

In one embodiment the present invention relates to a method of preparinga catalyst which comprises commingling a halogen with alumina,compositing platinum therewith, and subsequently heating the composite.

In another embodiment the present invention relates to a'method ofpreparing a catalyst which comprises forming a mixture of alumina con-'taining from about 0.5 to about 8% by weight of a combined halogen, andthereafter compositing platinum therewith.

In a. specific embodiment the present invention relates to a method ofpreparing a catalyst which comprises precipitating alumina from aluminumchloride, commingling hydrogen fluoride therewith in an amount offluorine from about 0.1 to about 3% ,by weight of said alumina, addinghydrogen sulfide to a chloroplatinic acid solution. commingling theresultant solution with said alumina, and thereafter heating theresultant composite at a temperature of from about 800 to about 1200 F.1

. In another specific embodiment the present invention relates to amethod of preparing a catalyst which comprises adding a basicprecipitant to aluminum chloride to form alumina, selectively washingsaid alumina to retain chloride ions in an amount of from about 0.2 toabout 8% by weight of said alumina, adding hydrogen sulfide to achloroplatinic acid solution, commingling the resultant solution withsaid alumina, and thereafter heating the resultant composite at atemperature of from about 800 to about 1200 F.

In still another embodiment the present invention relates to a novelcomposition of matter comprising alumina, platinum and from about 0.1%to about 5% by weight of a combined halogen.

As hereinbefore set forth, applicant has found that exceptionally goodcatalysts are prepared in accordance with the novel features of thepresent invention. While these catalysts may contain largerconcentrations of platinum, which may range up to about 10% by weight ormore of the alumina, it has been found that exceptionally good catalystsmay be prepared to contain as low as from about 0.01% to about 1% byweight of platinum. Catalysts of these low platinum concentrations areparticularly preferred in the present invention because of theconsiderably lower cost of the catalyst. It is well known that platinumis very expensive and any satisfactory method of reducing the amount ofplatinum required in catalysts considerably reduces the cost of thecatalyst and thus enhances the attractiveness of the catalystfor use incommercial processes. The platinum generally comprises a major portionof the cast of the catalyst and, therefore, by reducing the amount ofplatinum required to one half, for example, reduces the cost of thecatalyst substantially by one half. Further, for example, when theamount of platinum is reduced to about 0.1% by weight as against 5% byweight, or more, as heretofore required, it is readily apparent that thecost of the catalyst is reduced by at least 50 times.

However, in order to obtain improved results with these low platinumconcentrations, it is necessary that a particular type of supportingcomponent must be composited with the platinum. It has been found thatalumina shows unexpected advantages for use as a supporting componentfor the low platinum concentrations, apparently due to some peculiarassociation of the alumina withthe platinum, either as a chemicalcombination or merely as a physical association. It has been found thatthe specific combination of alumina and low platinum concentration isnotonly a very active catalyst, but also has a long catalyst life; that is,the catalyst retains its high activity for long periods of service.After these long periods of service, the catalyst may show a drop inactivity and it has further been found that the particular combinationof alumina and platinum renders the catalyst susceptible to readyregeneration.

To further improve these catalysts, it is an essential feature of thepresent invention that the final catalyst contains halogen ions in aspecific concentration. 'It has been found, and will be shown in thefollowing examples, that the presence of halogen ions within a specificrange enhances the initial activity of the catalyst and also serves toincrease the life of the catalyst.

chemical combination or loose complex with the alumina and/or platinum,and thereby serves to improve the final caltayst.

While any of the halogen ions will serve to effect improved results, thefluoride ions are preferred. Next in order are the chloride ions, whilethe bromide and iodide ions are generally less preferred. It isunderstood that, while all of these halogens will serve to effect animprovement, they are not necessarily equivalent.

The catalyst of the present invention may be prepared in any suitablemanner, a particularly preferred method is to prepare alumina by addinga suitable reagent, such as ammonium hydroxide, ammonium carbonate, etc.to a salt of aluminum, such as aluminum chloride, aluminum sulfate,aluminum nitrate, etc. in an amount to form aluminum hydroxide whichupon drying is converted to alumina and, in the interest of simplicity,the aluminum hydroxide is referred to as alumina in the presentspecification and claims in order that the percentages are based onaluminafree of combined water. It has been found that aluminum chlorideis generally preferred as the aluminum salt, not only for convenience insubsequent washing and filtering procedures, but also because it appearsto give best results. Another suitable method is to react sodiumaluminate with aluminum chloride or other suitable aluminum salt inorder to prepare the alumina.

After the alumina has been formed, it is generally washed to removesoluble impurities. Usual washing procedures comprise washing with'water, either in combination with filtration or as separate steps. Ithas been found that filtration of the alumina is improved when the washwater includes a small amount of ammonium hydroxide. The severity ofwashing will depend upon the particular method employed in preparing thecatalyst. In one embodiment of the invention, the alumina is thoroughlywashed with a suitable amount of water and preferably water containingammonium hydroxide to reduce the chlorine content of the alumina tobelow about 0.1%. In another embodiment of the invention this washingmay be selective to retain chloride ions in an amount of from about 0.2%to about by weight of the alumina on a dry basis. In accordanc with thismethod of preparing the catalyst. the chloride ions are obtained fromthe original aluminum chloride and are retained in 4 on the catalyst.The acetic acid apparently serves to peptize the alumina and therebyrenders it in a better condition for compositing with the platinum, andalso partly to fix the platinum on the alumina so that migration of theplatinum during subsequent heating is minimized. The amount of aceticacid, when employed, will generally be within the range of from about0.05 to the alumina, thus avoiding the necessity of adding the halogenions in a later step of catalyst preparation. However, it generally isdifiicult to control the washing procedure to retain the desired amountof halogen ion and, for this reason, it usually is preferred to wash thealumina to remove substantially all of the chloride ions and thereafteradd the halogen ions in a controlled amount. The addition of the halogenions in this manner permits better control of the amount of halogen ionsbeing added. In another embodiment of the invention, the washing may beselective to retain the chloride ions in an amount constituting aportion of the total halogen desired, and the remaining portion of thehalogen is then added in a subsequent step. In this method, the halogenion may comprise the same as for example chlorine and fluorine.

In some cases, it may be desired to commingle an organic acid andparticularly acetic acid which has been found to have a favorable effecthalogen or a mixture of two different halogens,

about 0.5 mol of acetic acid per mol of alumina.

Alumina prepared in the above manner, after washing and filtration, isgenerally recovered as a wet cake. The wet cake is usually made into aslurry with water and sent to a separate zone for further handling. Whenthe halogen ion is to be added separately, it preferably is done at thisstage of the catalyst preparation, that is, before the platinum iscommingled with the alumina. The halogen ion may be added in anysuitable manner. However, the halogen should be added in a form whichwill readily 'react with the alumina in order to obtain the desiredresults and also must not leave undesired deposits in the catalyst. Apreferred method of adding the halogen is in the form of an acid, suchas hydrogen fiuoride, hydrogen chloride, hydrogen bro"- mide and/orhydrogen iodide. Hydrogen fluoride is preferably added as an aqueoussolution for ease in handling and for control of the specific amount tobe added. Another saisfactory source to be used for adding the halogenis the volatile salts, such as ammonium fluoride, ammonium chloride,etc. The ammonium ions will be removed during the subsequent heating ofthe catalyst and, therefore, will not leave undesirable deposits in thecatalyst. In still another method, the halogen may be added as fluorine,chlorine, bromine, or iodine but, in view of the fact that fluorine andchlorine normally exist as a gas, it is generally preferable to utilizethem in the form of a solution for ease in handling. In somecases, theinclusion of certain components will not be harmful but may bebeneficial, and in these cases the halogen may be added in the form ofsalts such as potassium fluoride, sodium fluoride, thorium fluoride,sodium chloride, potassium chloride, etc.

The concentration of halogen ion in the finished catalyist will bewithin the range of from about 0.1% to about 8% by weight of the aluminaon a dry basis. The fluoride ion appears to be more active and,therefore, will be used within the range of from about 0.1% to about 3%by weight of the alumina on a dry basis. The chloride ion will be usedwithin the range of from about 0.2% to about 8% and preferably fromabout 0.5% to about 5% by weight of the alumina on a dry basis. It hasbeen found that halogen concentrations below these lower limits do notgive the desired improvement and, on the other hand, concentrations ofhalogen above the upper limits adversely affect the selectivity of thecatalyst, thus catalyzing side reactions to an extent greater thandesired.

After the alumina and halogen have been intimately mixed, the platinummay be added in any suitable manner. A particularly preferred method isto form a separate solution of chloroplatinic acid in water andintroduce hydrogen sulfide into this solution at room temperature, untilthe chloroplatinic acid solution reaches a constant coloration; that is,will not change color upon the addition of more hydrogen sulfide. 'Thechloroplatinic acid solution is normally light yellow and, upon additionof hydrogen sulfide gas, turns to a dark brown color. Apparently thechloroplatinic acid and hydrogen sulfide react to form one or morecomplex chemical compounds. Best results have been obtained in thismethod when the hydrogen sulfide is added at room temperature to thechloroplatinic acid solution. The addition of hydrogen sulfide atan'elevated temperature of 175 F. appears to produce less satisfactorycatalysts. The brown solution of chloroplatinic acid and hydrogensulfide may then be commingled with the slurry of wet alumina gel atroom temperature, and the slurry sufficiently stirred to obtain intimatemixing of the two solutions.

In the preferred embodiment of the invention the platinum is added in anamount to produce a final catalyst containing from about 0.01% to about1% by weight of platinum.

In another method of operation, chloroplatinic' acid solution may beadded to the slurry of alumina gel, and hydrogen sulfide then is addedto the mixture. In this method of operation it has been found that thehydrogen sulfide may be added at room temperature or at an elevatedtemperature of 175 F.

In some cases, satisfactory catalysts may-be produced by commingling thechloroplatinic acid solution with the slurry of alumina gel, and thendrying and heating in the manner hereinafterv set forth. In the method,hydrogen sulfide is not used. However, experiments have shown that thehydrogen sulfide addition is preferablebecause it tends to further fixthe platinum in the form of an insoluble compound on the alumina so thatthe platinum compound will not migrate during the subsequent heating ofthe catalyst.

It has been found that best results are obtained when the platinum iscomposited with the alumina before the alumina is subjected tosubstantial heating. As will be shown in the following examples, ahigher octane product was. obtained when the chloroplatinic acid wasadded to the wet alumina gel as compared to adding the chloroplatinicacid. to alumina which had previously been dried and formed into pills.

After the platinum in proper concentration .has been commingled with thealumina, the mixture is preferably dried at a temperature of from about200 to about 400 F. for a period of from about 4 to 24 hours or more toform a cake. In some cases it is desired to prepare the catalyst in theform of pills of uniform size and shape, and this may readily beaccomplished by grinding and partially dried catalyst cake, adding asuitable lubricant, such as stearic acid, rosin, hydrogenated coconutoil, graphite, etc., and then forming into pills in any suitablepelleting' apparatus. Particular satisfactory pills comprise those of asize ranging from about x to x A." or thereabouts. Pills of uniform sizeand shape may also be formed by extrusion methods. In some cases it maybe desired to utilize the catalyst as powder or granules of irregularsize and shape, in which cases the pilling and extrusion operations maybe omitted.

The catalyst may now be subjected to high temperaturetreatment, and thismay comprise one or several methods. Preferred method is to subject thecatalyst to' calcination at a temperaof from about 800 to about 1200 F.In still another method the catalyst may be subjected to reduction withhydrogen or hydrogen-containing gas at a temperature of from about 800to about 1200 F. for a period of from about 2 to 10 hours or more.

In some cases the lubricant will be removed during the hight temperatureheating. In oth r cases as, for example, when graphite is used as thelubricant, the separate high temperature heating step may be omitted,and the effective heat treatment of the catalyst may be obtained in theplant before or durin processing of the hydrocarbons.

Although the catalyst of the present invention will have a long life, itmay be necessary to regenerate the catalyst after long periods ofservice. The regeneration may be effected by treatment with air or otheroxygen-containing gas to burn carbonaceous deposits therefrom.Ingeneral, it is preferred to control the regeneration temperaturenot toexceed about 1200 F. In some cases it may be desirable to follow theburning operation with treatment with hydrogen-containing gas attemperatures of from about 700 to about 1100 F. p

The improved catalyst of the present invention may be employed in anyprocess for which platinum is a catalyst. The improved catalysts areparticularly satisfactory for reforming operations in which a saturatedgasoline, such as straight run gasoline, natural gasoline, etc. issubjected to conversion to produce a reformed gasoline of improvedanti-knock properties. The

saturated gasoline generally comprises a mixture of naphthenic andparafiinic hydrocarbons and the reforming operation effectsdehydrogenation of the naphthenic hydrocarbons to aromatics, cyclizationof the parafiinic hydrocarbons to aromatics, as well as to effect acontrolled type of cracking which is selective both in quality and inquantity. In addition, other reactions may occur such as isomerization,hydrogen transfer, etc. The controlled or selective cracking isdesirable because it further increases the octane number of the reformedgasoline, produces a gasoline of higher volatility and converts higherboiling fractions to lower boiling fractions within the range ofgasoline. However, this cracking must be controlled because excessivecracking produces excessive normally gaseous products and also excessivecarbonaceous deposits on and deactivation of the catalyst. The improvedcatalysts of the present invention are particularly desirable forreforming operations because the catalyst effects the desiredaromatization and controlled cracking under selected conditions ofoperation.

The catalyst of the present invention may also find utility in treatmentof higher boiling saturated fractions such as kerosene, gas oil, etc. Inmany cases it is desirable to produce from kerosene a highly aromaticproduct useful as a solvent, and the present invention is readilyapplicable for this purpose. The gasoline, kerosene, etc. fractionscomprise a mixture of different hydrocarbons and, in accordance with theinvention, the full boiling range fraction or any selected fractionthereof may be subjected to the desired conversion when a selectedfraction is so treated, it may be blended, all or in part, with theother fraction.

The catalyst of the present invention may prove particularly useful fordestructive hydrogenation or hydrocracking reactions in whichhydrocarbons and particularly oil heavier than asaasas gasoline issubjected. to conversion to produce lower boiling products andparticularly gasoline. For cracking reactions, it is preferred that thehalogen content of the catalyst be within the upper limits of the rangeshereinbeforeset forth because these higher halogen catalysts are moreactive for effecting decomposition reactions.

The catalyst of thepresent invention may also be useful for effectinghydrogenation reactions including the hydrogenation of unsaturatedaliphatic hydrocarbons, such as mono-olefins, diolefins, etc., to formthe corresponding saturated hydrocarbons, hydrogenation of unsaturatedcyclic hydrocarbons, hydrogenation of unsaturated alcohols, ketones,acids, etc. Other reactions in which these catalysts may find utilityinclude oxidation as, for example, oxidation of olefins to form thecorresponding oxide, such as the oxidation of ethylene to ethyleneoxide, propylene to propylene oxide, etc., oxidation of alcohols,ketones, etc. These and other oxidation reactions are well known in theart, and it is within the scope of the present invention to effect thesereactions in the presence of the novel catalysts. In reactions involvinghydrogenation, oxidation or condensation, it is preferred that thehalogen content of the catalyst be within the lower limits of the rangeshereinbefore specified in order to minimize side reactions.

As hereinbefore set forth, selected processing conditions are requireddepending upon the particular reaction desired. For reforming ofstraight run gasoline the temperature employed should be within therange of from about 600 to about 1000 F., the pressure within the rangeof from about 50 to about 1000 pounds per square inch and the weighthourly space velocity within the range of from about 0.5 to about 10.For dehydrogenation of normal butane the temperature should be withinthe range of from about 800 to about 1025 F. the pressure from aboutatmospheric to about 50 pounds per square inch and the gaseous hourlyspace velocity from about 200 to about 5000. For hydrogenation reactionsthe temperature may range from atmospheric to about 500 F., the pressurefrom about 100 to about 3000 pounds or more, and the weight hourly spacevelocity from about 0.5 to 5. The weight hourly space velocity isdefined as the weight of oil per hour per weight of catalyst in thereaction zone.

In one embodiment of the process, suificient hydrogen will be producedin the reforming reaction to furnish the hydrogen required in theprocess and, therefore, it may be unnecessary to either introducehydrogen from an extraneous source or to recycle hydrogen within theprocess. However, it usually will be preferred to introduce hydrogenfrom an extraneous source, generally at the beginning of the operation,and to recycle hydrogen within the process in order to be assured of asufficient hydrogen atmosphere in the reaction zone. In some cases thegas to be recycled will contain hydrogen sulfide, introduced with thecharge or liberated from the catalyst, and it is within the scope of thepresent invention to treat the hydrogen containing gas to removehydrogen sulfide or other impurities before recycling the hydrogenwithin the process.

The process of the present invention may be 7 upward or downward flow.The products are fractionated to separate hydrogen and to recover thedesired products. As hereinbefore set forth, the hydrogen may berecycled for further use in the process. Other suitable units in whichthe process may be effected include the fluidized type process in whichthe hydrocarbons and catalysts are maintained in a state of turbulenceunder hindered settling conditions in a reaction zone, the compact mov;bed type in which the catalyst and hydrocarbons are passed eitherconcurrently or'countercurrently to each other, and the suspensoid typeof operation in which the catalyst is carried into a reaction zone as aslurry in the hydrocarbon oil.

The following examples are introduced to'further illustrate the noveltyand utility of the present invention, but not with the intention ofunduly limiting the same.

EXAMPLEI This example shows the eflect of the addition of fluoride ionsto the alumina.

These catalysts were prepared by adding ammonium hydroxide to aluminumchloride hexahydrate. The resultant alumina was washed very thoroughlyin order to reduce the chlorine content of the alumina to below 0.1% byweight on a dry basis. This washing entailed six separate washes withlarge amounts of water containing a small amount of ammonium hydroxideand finally an additional wash with water. In one catalyst preparation(designated as catalyst No. 1 in the following table) hydrogen sulfideat room temperature was bubbled through an aqueous solution ofchloroplatinic acid and the resultant solution was added to the aluminain an amount to produce a final catalyst containing 0.1% by weight ofplatinum on a dry basis. The composite was then dried for 17 hours at'572' F. and then reduced with hydrogen at 932 F. for 3 hours.

A second catalyst was prepared in substantially the same manner as,described for catalyst No. 1, except that hydrogen fluoride wasintimately mixed with the alumina before the chloroplatinicacid-hydrogen sulfide solution was added thereto. The hydrogen fluoridewas added as a 4.8% aqueous solution and was added in an amount toproduce a final catalyst containing 1.5 by weight of fluorine.

These catalysts were used for the reforming of a Pennsylvania straightrun naphtha having a boiling range of from 226 to 350 F. and an A. S. T.M. motor method octane number of 41.8, at a temperature of about 874 F.,pressure of 500 pounds per square inch and a weight hourly spacevelocity of about 2. The liquid volume yield and the A. S. T. M. motormethod octane number of the products are indicated in the followingtable:

It will be noted that the catalyst containing fluorine yielded areformate of 19 octane numbers higher than the catalyst containing nofluorine.

of different amounts of fluorine to the catalyst. Catalysts No. 3 andNo.4 correspond to catalyst 10 centrations of chlorine produced higheroctane number products. However, the chlorine content should not beincreased above about 8% and preferably not above about because the 2 ofExample 1. catalysts 5 and No. 6 5 catalyst-will produce excessivehydrocracking and were prepared in substantially the same manner resultm an excess of gas formationas catalysts No. 3 and No. 4 except that theHF EXAMPLE IV solution was added in an amount to produce a This exampleshows the beneficial eiiects obflnal catalyst containing fluorine inamounts of tained in preparing the catalyst by the use of 3% forcatalyst No. 5 and 6% for catalyst No. 6. 10 hydrogen sulfides in themanner hereinbefore These catalysts were utilized for the reforming setforth. Catalysts No. 10 and No. 11 were of the same gasoline describedin Example I and prepared in substantially the same manner except underthe same'conditions of operation except that in catalyst No. 11 themixture of alumina that the temperature was varied as shown in the andchloroplatinic acid was heated to 140 F. f llowin table: 15 and hydrogensulfide was bubbled through the Table 2 v Rclorrnate Exit Gas, n ste rwe:

l Charge Charge L5 Fluorlne 824 95.9 3.6 05.1 1.5 a Fluorine... 874 83.2 6.9 78.8 Fluorine.-. 824 85 4. 9 71. 4 t Flu0rine... 755 77.6 4.5 12.4

It will be noted from the above data that the mixture for 15 minuteswith constant stirring. temperature and fluoride concentration, atacon-The results of these tests are indicated in the stant space velocity,must be correlated in order following table: to obtain the desiredresults. Referring to the Table 4 run with catalyst No. 3, it will benoted that the temperature is too low because the octane number of theproduct was only 65.7. However, when the. temperature was raised to 874F., the octane No. 0mmL Yield; Octane number was increased to 78.8.Using the lower 3-) 2? temperature (824 F.) with catalyst No. 5,satisoicharse factory results were obtained. However, even lowering thetemperature with catalyst No. ,6 con- 10 WiflmutHYdmsen Sulfide- 2 3training 6% fluorine, the octane number decreased. 11 Hydmge Sumde 7Therefore, the maximum fluorine content of the 40 catalyst should notexceed about 3%- It will be noted that the catalyst prepared by mm m theaddition of hydrogen sulfide gave a higher octane number product thanthe catalyst pre- This example shows the efiect of chlorine com pared nthe absence of hydrogen sulfide. tent of the catalyst. 5 Catalysts No.7, No. 8 and No. 9 comprised 0.1% EXAMPLE V Platinum-alumina The WashingPmcedures This example shows the improved results obwem to retain and35% tained by adding chloroplatinic acid to wet (Fluorine 1n the finalcatalyst alumina gel as compared to adding chloroplatinic 'l catalystswere used for the reforming of acid to alumina which had been dried andformed hiii t if 3.1 if? i Win22 0 3 an en 0 Catalyst No. 12 wasprepared in substantially P i of 339 and an motol metmd the same manneras hereinbefore set forth, while octane number of These testso werecatalyst No. 13 was prepared by adding chloroducted at temperature ofabout 872 a Pres platinic acid to alumina pills which previously sure ofabout 500 pounds per square inch and a had been meet sp e velocity ofabout The results of these These catalysts were used for the reformingof tests are shown in the following table: a Mid-Continent straight runnaphtha having Table 3 an initial boiling point of 217 F., an endboiling point of 392 F. and an A. S. T. M. motor method Liquid octanenumber of 38.9. The reforming was vol m effected at a temperature of 752F., pressure Catalyst nf gmgg of 200 pounds per square inch and a spacePer ent velocity of 1. The results are shown in the Charge followingtable:

1 0.57 Chlorine", 92.3 64.2 Table 5 a. 1.5 0 Chlorine 89.5 74.6 0 3.5%Chlorine 03.4 76

' Liquid N Octane It will be noted that the catalyst containing @332?Number 0.5% chlorine produced a reformate of 64.2 octane number.Therefore, the chloride content of 2 Pl num ded to wet 92.8 as: thecatalyst preferably is not below about 0.5% 13 rism? ,3333%- to dry 97.6m

and certainly should not be below about 0.1%. alumina p Catalysts No. 8and No. 9 containing higher con- 11 It will be noted that the additionof chloroplatinic acid to wet alumina slurry produced a considerablyhigher octane number product under the same conditions of operation.

EXAMPLEVI This example shows the effect of temperature of hydrogensulfide addition in catalysts prepared by adding the hydrogen sulfide'tothe chloroplatinic acid solution and then adding this mixture to the wetalumina slurry. In catalyst No. 14 the hydrogen sulfide was added atroom temperature, whereas in catalyst No. 15 the hydrogen sulfide waspassed through a solution of chloroplatinic acid. at 176 F. Thesecatalysts were tested in the reforming of a Pennsylvania straight runnaphtha having an initial boiling point of 226 F., and end boiling pointof 350 F. and an A. S. T. M. motor method octane number of 41.8. Theresults of these tests are shown in the following table:

Table 6 Liquid cm No. Gatal c Volume Yield Number 14 Hydrogcnsulildeadded at ca. 1 00.1

room temperature. fligigog en sulfide added at 97. 7 56. 4

It will be noted that the catalysts prepared by adding the hydrogensulfide at room temperature produced a somewhat higher octane numberproduct than the catalyst prepared by adding the hydrogen sulfide at anelevated temperature.

EXAMPLEVII Table 7 Liquid 0 ta No. Catalyst Volume c Yield Number 10Hydrogen sulfide added at 04. 4 63. 8

room temperature. 17 Bygigngogen sulfide added at 95. 6 62. 8

It will be noted that the results are fairly comparable in these testsand that the eflect of temperature of hydrogen sulfide treatment is notsubstantial in catalysts prepared by adding hydrogen sulfide to. thechloroplatinic acid-alumina gel mixture.

EXAMPLE VIII In view of the very low concentrations of platinum found tobe effective in catalyzing the reforming operation, the questionsnaturally arise as to whether such small amounts of platinum areactually of any effect and whether the platinum can not be omitted andthe'same results the catalyst prepared by obtain. In order to definitelyshow that im- 12 were prepared in substantiallythe same manner exceptthat one catalyst comprised 0.1% by weight of platinum composited withalumina. and the other catalyst comprised alumina but contained noplatinum.

In a reforming operation, a Pennsylvania straight run naphtha having aboiling range of from 226 F. to 350 F. and an A. S. T. M. motor methodoctane number of 41.8 was subjected to conversion in the presence of theplatinum-containing catalyst and in the presence of the catalystcontaining no platinum at a temperature of about 872 F., a pressure of500 pounds per square inch and a weight hourly space velocity of about2. The liquid volume yield and the A. S. T. M. motor method octanenumber of the products are indicated in thefollowing table:

Table 8 l iii uld 0 me Octane No. Catal t Yield ys Per Cent Number oiCharge 18. 0.1% Platinum Alumina-. are so 19 Alumina... 90 50.6

It will be noted that the catalyst containing no platinum yielded aproduct of 50.6 octane number, whereas the platinum containing catalystyielded a product of octane number. It is readily apparent that the 0.1%by weight of platinum exerts a definite catalytic efiect.

I claim as my invention:

1. A method of manufacturing a catalyst which comprises adding a basicprecipitant to aluminum chloride to form alumina containing chlorine,washing said alumina to retain therein from about 0.1% to about 8% byweight of said chlorine, commingling a platinum containing solutiontherewith, drying the resultant composite and then calcining the same.

2. A method of preparing a catalyst which comp r i s e s precipitating achlorine-containing alumina from aluminum chloride, washing said aluminato retain therein from about 0.1% to about 8 by weight of said chlorine,commingling therewith a platinum containing solution in an amount toform a final catalyst containing from about 0.01% to about 1% by weightof platinum. drying the composite and then calcining the same at atemperature of from about 800 to about 1200 1".

3. A method of preparing a catalyst which comprises precipitating achlorine-containing alumine, from aluminum chloride, selectively washingsaid alumina to retain therein from about 0.1% to about 5% by weight'ofsaid chlorine, commingling therewith a chloroplatinic acid solution inan amount to atorm a final catalyst containing from about 0.01% to about1% by weight of platinum, drying the composite and then calcining thesame at a temperature 'of from about 800 to about 1200 F.

4. A method of preparing a catalyst which comprises precipitating achlorine-containing alumina from aluminum chloride, selectively washingsaid alumina to retain therein from about 0.1% to about 8% by weight ofsaid chlorine, separately commingling hydrogen sulfide with achloroplatinic acid solution, commingling the resultant solution withthe alumina containing combined chlorine, and thereafter heating theresultant composite at a temperature of from about 800 to about 1200 F.

13 14 5. A method of manufacturing a catalyst REFERENCES CITED whichcomprises adding a basic precipitant to a The following references areof record in the chloride of aluminum to form alumina contalnme of thispatent:

ing chlorine, washing said alumina to retain therein from about 0.1% toabout 8% by weight UNITED STATES PATENTS of said chlorine, comminglingwith the chlorine- Numler Name Date containing alumina a solution of aplatinum 612, 615 Porter Oct. 18, 1898 compound in an amount to form afinal catalyst 2, 461, 959 Brandon Feb. 15, 1949 containing from about0.01% to about 10% by 2,475,155 Rosenblatt July 5, 1949 weight ofplatinum, drying the resultant com- 10 2,479,110 Haensel Aug.16,1949

posite and then calcining the same at a temperature of from about 800 toabout 1200 F.

VLADIMIR HAENSEL.

1. A METHOD OF MANUFACTURING A CATALYST WHICH COMPRISES ADDING A BASICPRECIPITANT TO ALUMINUM CHLORIDE TO FORM ALUMINA CONTAINING CHLORINE,WASHING SAID ALUMINA TO RETAIN THEREIN FROM ABOUT 0.1% TO ABOUT 8% BYWEIGHT OF SAID CHLORINE, COMMINGLING A PLATINUM CONTAINING SOLUTIONTHEREWITH, DRYING THE RESULTANT COMPOSITE AND THEN CALCINING THE SAME.